Characteristics of sorption losses of polychlorinated biphenyl congeners onto glass surfaces

Sorption losses to glass surfaces of five polychlorinated biphenyl (PCB) congeners in aqueous solutions were investigated. Adsorption/desorption experiments were conducted under conditions that simulated actual sample handling procedures for environmental samples. It was found that the adsorption loss is related to the degree of chlorination. PCB congener 180 lost the most onto glass surfaces, followed by congeners 138, 101/28, and 52, in decreasing order. More PCB adsorption occurred onto glass under conditions of agitation and higher temperature (22°C) during the five-day experimental period. The salinity effect (“salting out effect”) was also observed in this work. The efficiency of desorption (rinsing three times with solvent) was found to be ineffective in extracting adsorbed PCBs. It was necessary to use mechanical shaking for extraction. Storage of samples up to five days resulted in sorption losses as much as 30%, 17%, 30%, 40%, and 55% of PCB 28, 52, 101, 138, and 180, respectively. Sorption losses need to be considered when conducting water sampling or toxicological studies to avoid underestimation of the actual PCB concentrations and their toxic effects.     

The relationship between ecology and the incidence of cooperative breeding in Australian birds

Summary Australia has many cooperatively breeding species of birds. These tend to occur in eucalypt and semi-arid woodlands rather than in rainforests or deserts. They tend to be insectivores that pursue rather than sit and wait for their prey, and tend to forage on the ground rather than above it. We propose that environments where resources do not show marked seasonal fluctuations are those in which cooperative breeding is most likely to evolve. Under these conditions birds might experience difficulty acquiring the extra food necessary to breed, especially if inexperienced. When adult survival was high, young and inexperienced birds could delay breeding. Unpredictable environments may also favor cooperative breeding, but our data do not strongly support this. Groupliving would be favored further if young birds are particularly vulnerable to predators when alone. They should therefore remain in the family group and delay their dispersal unitl a suitable breeding vacancy becomes available. These hypotheses are not mutually exclusive, but are complementary. Both may be required to ensure that at least some year-old birds do not breed and also do not disperse. We believe that they give rise to predictions, which can be tested in future field studies.     

Measurement of calcium carbonate deposition in molluscs by controlled etching of radioactively labeled shells

Rates of calcium carbonate removal from shell pieces of Argopecten irradians (Say) and Mercenaria mercenaria (L.) were dependent on the type of etching fluid used and not shell origin. Etching was uniform over the entire shell surface, but surface morphology differed with etching fluids. Peak radioactivity was in early eluant fractions of shells etched immediately after radioactive labeling, and in later fractions when individuals were placed in isotope-free seawater after labeling. The etching technique can measure growth during the labeling period and subsequently by estimating the amount of calcium in fractions prior to the radioactive peak. Geometry of shell layers influenced the pattern of radioactivity seen in fractions. Peak location varied inside and outside the pallial line of individual M. mercenaria. A significant portion of the inorganic carbon used in shell formation by M. mercenaria was derived from metabolic CO₂.     

The 4Cs of adaptation tracking: consistency,comparability, comprehensiveness,coherency

Adaptation tracking seeks to characterize, monitor, and compare general trends in climate change adaptation over time and across nations. Recognized as essential for evaluating adaptation progress, there have been few attempts to develop systematic approaches for tracking adaptation. This is reflected in polarized opinions, contradictory findings, and lack of understanding on the state of adaptation globally. In this paper, we outline key methodological considerations necessary for adaptation tracking research to produce systematic, rigorous, comparable, and usable insights that can capture the current state of adaptation globally, provide the basis for characterizing and evaluating adaptations taking place, facilitate examination of what conditions explain differences in adaptation action across jurisdictions, and can underpin the monitoring of change in adaptation over time. Specifically, we argue that approaches to adaptation tracking need to (i) utilize a consistent and operational conceptualization of adaptation, (ii) focus on comparable units of analysis, (iii) use and develop comprehensive datasets on adaptation action, and (iv) be coherent with our understanding of what constitutes real adaptation. Collectively, these form the 4Cs of adaptation tracking (consistency, comparability, comprehensiveness, and coherency).     

Vulnerability to the health effects of climate variability in rural southwestern Uganda

Vulnerability to the health impacts of climate change will be shaped by the existing burden of ill- health and is expected to be highest in poor and socio-economically marginalized populations. Sub-Saharan Africa, in particular, is considered a highly vulnerable region. This paper analyses the vulnerability and adaptive capacity of rural Bakiga communities in southwestern Uganda to climate-sensitive health risks. The objectives were threefold: i) identify key climate-sensitive, community-identified health priorities; ii) describe and characterize determinants of sensitivity to these health priorities at the individual, community and regional levels; and iii) assess the adaptive capacity of Bakiga. Data collection employed a combination of individual and key informant interviews, biographies, future storylines, and Photovoice. Three key health risks were identified by the study communities (malaria, food insecurity, and gastrointestinal illnesses) – all affected by local climatic and environmental conditions, livelihoods, land use changes, and socio-economic conditions. Adaptation within these communities is dependent on their capacity to reduce sensitivities to identified health challenges among the potential of increasing exposures. Crop diversification, reducing deforestation, expanding of livestock rearing, transfer of traditional knowledge, and access to affordable health services are among potential strategies identified. We demonstrate significant existing vulnerabilities to present day climate-related health risks and highlight the importance of non-climatic processes and local conditions in creating sensitivity to health risks. Our place-based understanding is useful to inform interventions or policies aimed to reduce exposure and sensitivity and support adaptive capacity as the conditions these communities face are consistent with many other sub-Saharan African countries.     

Climate change and mining in Canada

Climate is an important component of the operating environment for the Canadian mining sector. However, in recent years mines across Canada have been affected by significant climatic hazards, several which are regarded to be symptomatic of climate change. For the mining sector, climate change is a pressing environmental threat and a significant business risk. The extent to which the mining sector is able to mitigate its own impact and adapt to climate change will affect its long-term success and prosperity, and have profound economic consequences for host communities. This paper draws upon case studies conducted with mining operations in Canada involving in-depth interviews with mining professionals and analysis of secondary sources to characterize the vulnerability of the Canadian mining industry to climate change. Five key findings are discussed: i) mines in the case studies are affected by climate events that are indicative of climate change, with examples of negative impacts over the past decade; ii) most mine infrastructure has been designed assuming that the climate is not changing; iii) most industry stakeholders interviewed view climate change as a minor concern; iv) limited adaption planning for future climate change is underway; v) significant vulnerabilities exist in the post-operational phase of mines. This paper argues for greater collaboration among mining companies, regulators, scientists and other industry stakeholders to develop practical adaptation strategies that can be integrated into existing and new mine operations, including in the post-operational phase.     

Deleterious effects of a nonPST bioactive compound(s) from <Emphasis Type="Italic">Alexandrium tamarense</Emphasis> on bivalve hemocytes

The known negative effects of shellfish toxin-producing dinoflagellates on feeding, burrowing and survival of some bivalve mollusks has prompted questions concerning whether they might also impair the internal defense system of affected bivalves and make them more susceptible to disease agents. The primary components of the cellular defense system are hemocytes. Many toxic dinoflagellates are too large to be ingested whole by hemocytes and would most likely be exposed to intracellular toxins only after the algae are consumed, broken down, and the water-soluble toxins, released. Therefore, we conducted a series of experiments in which hemocytes from two suspension-feeding bivalves—the Manila clam, Ruditapes philippinarum, and the softshell clam, Mya arenaria—were exposed in vitro to filtered extracts of one highly toxic paralytic shellfish toxin (PST)-producing and one nonPST-producing strain of Alexandrium tamarense (isolates PR18b, 76 ± 6 STXeq cell⁻¹ and CCMP115, with undetectable PST, respectively). We measured adherence and phagocytosis, two hemocyte attributes known to be inhibited by bacterial pathogens and other stressors. We found no measurable effect of a cell-free extract from a highly concentrated suspension of the PST-producing strain on hemocytes of either bivalve species. Instead, extract from the nonPST-producing strain had a consistent negative effect on both clams, resulting in significantly lower adherence and phagocytosis compared to strain PR18b and filtered seawater controls. The bioactive compound produced by strain CCMP115, which has yet to be characterized, may be similar to the PST-independent allelopathic compounds described for Alexandrium spp., which act on other plankters. These compounds and those produced by other harmful algae are known to cause immobilization, cellular deformation and lysis of co-occurring target organisms. Thus, nonPST producing Alexandrium spp., which do not cause paralysis and burrowing incapacitation of clams, may still produce a compound(s) that has negative effects not only on hemocytes, but on other molluscan cell types and their functions, as well.     

Financial inadequacy and the disadvantageous changes in time perspective and goal-striving strategies throughout life

As inequality in wealth and income continues to grow, it is important to consider the implications of financial disparities for worker motivation and behavior. While workers with socioeconomic disadvantages have a decreased chance of career success and upward social mobility, the potential mechanisms linking financial status to work motivation outcomes are not fully known. Drawing on theory on resource scarcity, we address this issue and propose that financial inadequacy shapes the extent to which workers consider and plan for the future, with consequences for goal-striving strategies throughout adulthood. Latent change analyses of data from a heterogeneous sample of 4,446 working adults largely supported the hypotheses. Results showed that a high level of financial inadequacy predicted increases in short-term time horizon and decreases in future-oriented planning, which then predicted disadvantageous changes in goal-striving strategies over an 18-year period. Short-term time horizon also predicted subsequent increases in financial inadequacy. By highlighting the motivational challenges associated with inadequate finances that accompany low-wage employment, our study offers evidence for the motivational mechanisms that may reinforce economic inequality and social mobility in the workforce.     

Human–wildlife coexistence in a changing world

Human–wildlife conflict (HWC) is a key topic in conservation and agricultural research. Decision makers need evidence-based information to design sustainable management plans and policy instruments. However, providing objective decision support can be challenging because realities and perceptions of human–wildlife interactions vary widely between and within rural, urban, and peri-urban areas. Land users who incur costs through wildlife argue that wildlife-related losses should be compensated and that prevention should be subsidized. Supporters of human–wildlife coexistence policies, such as urban-dwelling people, may not face threats to their livelihoods from wildlife. Such spatial heterogeneity in the cost and benefits of living with wildlife is germane in most contemporary societies. This Special Section features contributions on wildlife-induced damages that range from human perspectives (land use, psychology, governance, local attitudes and perceptions, costs and benefits, and HWC and coexistence theory) to ecological perspectives (animal behavior). Building on current literature and articles in this section, we developed a conceptual model to help frame HWC and coexistence dimensions. The framework can be used to determine damage prevention implementation levels and approaches to HWC resolution. Our synthesis revealed that inter- and transdisciplinary approaches and multilevel governance approaches can help stakeholders and institutions implement sustainable management strategies that promote human–wildlife coexistence.     

Mapping Human Dimensions of Climate Change Research in the Canadian Arctic

This study maps current understanding and research trends on the human dimensions of climate change (HDCC) in the eastern and central Canadian Arctic. Developing a systematic literature review methodology, 117 peer reviewed articles are identified and examined using quantitative and qualitative methods. The research highlights the rapid expansion of HDCC studies over the last decade. Early scholarship was dominated by work documenting Inuit observations of climate change, with research employing vulnerability concepts and terminology now common. Adaptation studies which seek to identify and evaluate opportunities to reduce vulnerability to climate change and take advantage of new opportunities remain in their infancy. Over the last 5 years there has been an increase social science-led research, with many studies employing key principles of community-based research. We currently have baseline understanding of climate change impacts, adaptation, and vulnerability in the region, but key gaps are evident. Future research needs to target significant geographic disparities in understanding, consider risks and opportunities posed by climate change outside of the subsistence hunting sector, complement case study research with regional analyses, and focus on identifying and characterizing sustainable and feasible adaptation interventions.